What is a DJ (disc jockey)? -
A DJ is a person who selects and plays prerecorded music for an audience, either on radio, online content in the form of podcasts or web-based radio shows (see websites), or at a club.
There are several types of DJs: radio DJs play music that is broadcast on AM, FM, shortwave or digital radio stations; club DJs select and play/mix music in a club, disco, a rave, or even a stadium; and mobile disc jockeys travel with mobile sound systems and play from an extensive collection of pre-recorded music. (Including but not limited to: weddings, private parties, etc)

Equipment:

TURNTABLES (decks, tt’s)-
A turntable (known to many as a record player) has a constant speed. The motor or belt driven “platter” revolves part of the turntable on which the record rests while it is being played. The increasingly skillful use of turntables by DJs to mix and scratch records has given rise to the term turntablism.
In all turntables a motor spins a metal disk at a constant speed. On top of the rotating disk (platter) is a mat and on top of the mat records are placed to be played. In the past rubber mats were used to hold the record in place so that it would not rotate independently of the platter. Nowadays slipmats are used to reduce the friction between the spinning platter and record, and is often made of a felt like material. This way a DJ can scratch the record while the platter continues to spin underneath. In direct drive turntables the slipmat also helps isolate the record from motor vibrations that would be picked up by the stylus.
Many turntables also include a pitch control, which allows a DJ to mix using a technique known as beatmatching. From the late 1990s onwards manufacturers such as Vestax started to include other electronic controls such as reverse, and "nudge".
DJs and Turntablists have learned to use all the above functions assist them in musical performances.

Turntablism is the art of manipulating sounds and creating music using turntables and a DJ mixer. The term was created in 1994 by DJ Supreme to describe the difference between a DJ who just plays records, and one who actually performs, by touching and moving the records to manipulate sound. The word was never meant to be the actual title of the art form. It was regularly stated as an example, while explaining the need for a new word to describe a newly emerging and totally unique instrumental art form. The intention was for the original creators of the art form to brainstorm and decide on a title. While the idea of the need for a new word spread, some DJs just began to use the example word "turntablist" before the originators had a chance to proclaim an actual title.
DJ Babu has defined a turntablist as "One who has the ability to improvise on a phonograph turntable. One who uses the turntable in the spirit of a musical instrument;" while the Battlesounds documentary film suggests a definition of:"A musician, a disc jockey who in a live/spontaneous situation can manipulate or restructure an existing phonograph recording (in combination with an audio mixer) to produce or express a new composition that is unrecognizable from its original ingredients."
Turntablist DJs use turntable techniques like beat mixing/matching, scratching, and beat juggling. Turntablism is generally focused more on turntable technique and less on mixing. Some turntablists seek to have themselves recognized as legitimate musicians capable of interacting and improvising with other performers.

All of which rose from the phonograph, or gramophone, which was the most common device for playing recorded sound from the 1870s through the 1980s. (Google it)

Types of Turntables:

- Belt Drive: In a belt drive turntable the motor is located under and to the side of the platter and is connected to the platter by an elastometric belt.
The design of the belt drive turntable allows the use of a less expensive motor than the direct-drive turntable.
Pros: The elastometric belt absorbs motor vibrations which would otherwise be picked up by the stylus. Problems with belt instability and deterioration in the past have largely been solved by use of modern elastic polymers.
Cons: Over time the drive belt can wear or lose elasticity, and begin to slip, causing variations in the platter speed. In addition, belt drive turntables have much lower torque; the belt can also slip off the motor and/or platter spindle, and are thus not suitable for turntablism. DJs who scratch or mix generally prefer to use direct-drive turntable.

- Direct Drive: In a direct drive turntable the motor is located directly under the center of the platter and is connected to the platter directly. The first commercially available direct-drive turntable, the model SP-10, was introduced by the Technics division of Matsushita in 1969.
Cons: The sole disadvantage to direct drive turntables over belt-drive turntables is vibration from the motor.
Pros: Shock-absorbing (less dense) material, placed between the motor and platter, has been used to cut back on vibrations. Since the motor is directly connected to the platter, the torque is usually much higher than in the belt drive models (stronger motor). Higher torque means the platter speed is less susceptible to outside forces (stylus, hand). Higher torque also means the platter will accelerate to its proper speed faster so less distortion is heard when the record begins to play.

Each turntable brand has a different turntable model with different specifications. (Technics, Numark, Vestax, Gemini, etc.) Research before you buy and look at specifications of whatever TT you’re interested in. Technics have been around for a long time and are trusted by DJ’s across the world. Numark’s however picked up Tech’s patent and added on with their TTx1 model, however they haven’t been around as long therefore, haven’t “proven” themselves to some DJ’s. In the end, it’s up to what you’re comfortable with. Let nobody tell you otherwise.

* Recommended: (direct drive) Technics, Numark, Vestax

RECORDS (vinyl, wax) -
Records are the analogue sound recording medium consisting of a flat disc with an inscribed modulated spiral groove starting near the periphery and ending near the center of the disc.
Early disc records were made of various materials including hard rubber. From 1897 onwards, earlier materials were largely replaced by a rather brittle formula of 25% "shellac" (a material obtained from the excretion of a Southeast Asian beetle), a filler of a cotton compound similar to manila paper, powdered slate, and a small amount of a wax lubricant. The mass production of shellac records began in 1898 in Hanover, Germany. Shellac records were the most common until the 1950s. Unbreakable records, usually of celluloid (an early form of plastic) on a pasteboard base, were made from 1904 onwards, but they suffered from an exceptionally high level of surface noise
The terms LP and EP are acronyms of Long Play and Extended Play respectively, these type designations refer to their rotational speeds in revolutions per minute (RPM). Records nowadays are usually made of polyvinyl chloride (PVC), and hence may be referred to as vinyl records or simply vinyl.

MIXERS (board) -
A DJ mixer is a type of audio mixing console used by DJ. The key features that differentiate a DJ mixer from other types of audio mixers are the ability to redirect (cue) a non-playing source to headphones and the presence of a crossfader, which allows for an easier transition between two sources.
A typical modern DJ mixer generally has between two and six stereo channels for connecting and mixing audio sources. Each channel usually has a phono input with RIAA* equalization for turntables and one or two line level inputs for sources such as CD players. Controls for individual channels are arranged in vertical columns (channel strips), starting with a switch or a knob selecting between the inputs.

*specification for the correct playback of vinyl records, established by the Recording Industry Association of America

Phono level is a signal produced at a very low level by a magnetic phono cartridge which must be amplified and equalized. Phonograph recordings are made with high frequencies boosted. This reduces background noise, including clicks or pops, and also conserves the amount of physical space needed for each groove, by reducing the size of the larger low-frequency undulations. During playback the high frequencies are rescaled to their original level. This is accomplished in the amplifier with a "PHONO" input that incorporates standardized RIAA equalization circuitry.

Line level is a term used to denote the strength of an audio signal used to transmit analog sound information between audio components such as CD and DVD players, TVs, audio amplifiers, and mixing consoles.
The strength of the various signals does not necessarily correlate with the output voltage of a device; it also depends on the source's output impedance, or the amount of current available to drive different loads.

HEADPHONES (cans)-
Headphones let the DJ listen to any channel in the headphones independently of what is playing on the speakers, allowing the DJ to beatmatch the records by ear; this became the defining feature of DJ mixers.

CARTRIDGE, HEADSHELL, NEEDLE, TONEARM
A cartridge is a transducer used for the playback of records on a turntable or phonograph. It converts mechanical vibrational energy from a stylus (needle) riding in a spiral record groove into an electrical signal that is subsequently amplified and then converted back to sound by a speaker system.
The stylus fits into the cartridge, which is bolted to the Headshell. The headshell holds the cartridge, and includes the proper weight, height, and wiring to transfer the signal of the media source.
This all leads to the tonearm. The tonearm holds the pickup cartridge over the groove, the stylus tracking the groove with the desired force to give the optimal compromise between good tracking and minimizing wear of the stylus and record groove. At its simplest, a tone arm is a pivoted lever, free to move in two axes (vertical and horizontal) with a counterbalance to maintain tracking pressure.

SPEAKERS (Passive & Active) -
A passive speaker (or unpowered speaker) is a speaker which does not have its own power source and has to draw power from somewhere else, opposed to an active speaker which has a built-in amplifier.
Active speakers have a short run of cable between the amplifier and the speaker, which prevents signal and power loss. The amplifier can also be matched to the speaker more exactly.
Passive speakers are lighter and cheaper however, but require longer lengths of cable to run to a separate amplifier. This can be desirable if you have amplifiers that can run multiple speakers. Passive are easier to come by, and unless you’re gigging a club or need a really nice sound system for events, most people use passive speakers.

Recommendations: KRK’s, JBL’s, B-52

SLIPMATS -
A slipmat is a circular piece of slippery cloth or synthetic materials used by disk jockeys instead of the traditional rubber mat.
Unlike the rubber mat which is made to keep hold the record firmly in sync with the rotating platter, slipmats are designed to slip on the platter, allowing the DJ to manipulate a record on a turntable while the platter continues to rotate underneath. This is useful for holding a record still for slip-cueing, making minute adjustments during beatmatching and mixing and pulling the record back and forth for scratching.

.Mp3’s and .Wav’s (popular digital formats)
Mp3: MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular audio encoding format. It uses a lossy compression algorithm that is designed to greatly reduce the amount of data required to represent the audio recording (unlike .wav’s), yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. It was invented by a team of European engineers at Philips, CCETT (Centre commun d'études de télévision et télécommunications), IRT and Fraunhofer Society, who worked in the framework of the EUREKA 147 DAB digital radio research program, and it became an ISO/IEC standard in 1991.
MP3 is an audio-specific format. The compression takes off certain sounds that cannot be heard by the listener, i.e. outside the normal human hearing range. It provides a representation of pulse-code modulation–encoded audio in much less space than straightforward methods, by using psychoacoustic models to discard components less audible to human hearing, and recording the remaining information in an efficient manner.

.Wav: (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. It is a variant of the RIFF bitstream format method for storing data in "chunks", and thus also close to the IFF and the AIFF format used on Amiga and Macintosh computers, respectively. It is the main format used on Windows systems for raw audio.
Though a WAV file can hold compressed audio, the most common WAV format contains uncompressed audio in the pulse-code modulation (PCM) format. PCM audio is the standard audio file format for CDs at 44,100 samples per second, 16 bits per sample. Since PCM uses an uncompressed, lossless storage method, which keeps all the samples of an audio track, professional users or audio experts may use the WAV format for maximum audio quality. WAV audio can also be edited and manipulated with relative ease using software.

Vinyl Emulation

DVS / Digital Systems (digital)
Digital DJ systems / programs allow manipulation and playback of digital audio files (mp3, wav, aiff, ogg) using traditional vinyl turntables or CD players via special timecode vinyl records or CDs. It seeks to cross the divide between the versatility of digital audio and the tactile control of vinyl turntablism.
Concept: Special vinyl records (or cd’s) pressed with a digital timecode are played on normal turntables. The timecode signal is interpreted by a computer, connected to the turntables through an interface (soundcard or some sort usually.) The signal represents where the stylus is on the record, in which direction it is traveling, and at what speed. This information is interpreted by the computer and used to play back a digital audio file which has been 'mapped' to the turntable.
In practical terms, this means that any audio file can be manipulated as though it were pressed on vinyl. This has a great many advantages for DJs, not least that a laptop computer can often hold tens of thousands of audio files, whilst a record box has a decidedly smaller capacity and is much heavier.

MIDI (Musical Instrument Digital Interface) & MIDI Controllers –
MIDI is an industry-standard electronic communications protocol that enables electronic musical instruments, computers and other equipment to communicate, control and synchronize with each other in real time.
MIDI does not transmit an audio signal or media — it simply transmits digital data "event messages" such as the pitch and intensity of musical notes to play, control signals for parameters such as volume, vibrato and panning, cues and clock signals to set the tempo. As an electronic protocol, it is notable for its success, both in its widespread adoption throughout the industry, and in remaining essentially unchanged in the face of technological developments since its introduction in 1983.
MIDI controller is used in two senses.
• In one sense, a controller is hardware or software which generates and transmits MIDI data to MIDI-enabled devices.
• In the other more technical sense, a MIDI controller is an abstraction of the hardware used to control a performance, but which is not directly related to note-on/note off events. A slider assigned to open and close a low-pass filter on a synthesizer may be assigned to controller 18, for example. Changes in the position of the slider are transmitted along with "18" so that they are distinguished from changes in the value of other controllers.
MIDI controllers which are hardware and software
The following are classes of MIDI controller:
• The human interface component of a traditional instrument redesigned as a MIDI control device. The most common type of device in this class is the keyboard controller. Such a device provides a musical keyboard and perhaps other actuators (pitch bend and modulation wheels, for example) but produces no sound on its own. It is intended only to drive other MIDI devices. Percussion controllers such as the Roland Octapad fall into this class, as do guitar-like controllers such as the SynthAxe and a variety of wind controllers.
• Electronic musical instruments, including synthesizers, samplers, drum machines, and electronic drums, which are used to perform music in real time and are inherently able to transmit a MIDI data stream of the performance.
• Pitch-to-MIDI converters including guitar/synthesizers analyze a pitch and convert it into a MIDI signal. There are several devices which do this for the human voice and for monophonic instruments such as flutes, for example.
• Traditional instruments such as drums, pianos, and accordions which are outfitted with sensors and a computer which accepts input from the sensors and transmits real-time performance information as MIDI data.
• Sequencers, which store and retrieve MIDI data and send the data to MIDI enabled instruments in order to reproduce a performance.
• MIDI Machine Control (MMC) devices such as recording equipment, which transmit messages to aid in the synchronization of MIDI-enabled devices. For example, a recorder may have a feature to index a recording by measure and beat. The sequencer that it controls would stay synchronized with it as the recorder's transport controls are pushed and corresponding MIDI messages transmitted.
• MIDI Show Control (MSC) devices such as show controllers, which transmit messages to aid in the operation and cueing of live theatrical and themed entertainment productions. For example, a variety of show control sub systems such as sound consoles, sound playback controllers, virtual audio matrices and switchers, video playback systems, rigging controllers, pyro and lighting control systems directly respond to MSC commands. However, most standalone generic MSC controllers are intended to actuate a generic computerised show control system which has been carefully programmed to produce the complex desired results that the show demands at each moment of the production.

EFFECTS (fx) - Sound effects or audio effects are artificially created or enhanced sounds, or sound processes used to emphasize artistic or other content of movies, video games, music, or other media.
In music, typical effects used in recording and amplified performances are:
• Echo - one or several delayed signals are added to the original signal. To be perceived as echo, the delay has to be of order 50 milliseconds or above. Short of actually playing a sound in the desired environment, the effect of echo can be implemented using either digital or analog methods. Analog echo effects are implemented using tape delays and/or spring reverbs. When large numbers of delayed signals are mixed over several seconds, the resulting sound has the effect of being presented in a large room, and it is more commonly called reverberation or reverb for short.
• Flanger - a delayed signal is added to the original signal with a continuously-variable delay (usually smaller than 10 ms). This effect is now done electronically using DSP, but originally the effect was created by playing the same recording on two synchronized tape players, and then mixing the signals together. As long as the machines were synchronized, the mix would sound more-or-less normal, but if the operator placed his finger on the flange of one of the players (hence "flanger"), that machine would slow down and its signal would fall out-of-phase with its partner, producing a phasing effect. Once the operator took his finger off, the player would speed up until its tachometer was back in phase with the master, and as this happened, the phasing effect would appear to slide up the frequency spectrum. This phasing up-and-down the register can be performed rhythmically.
• Phaser - the signal is split, a portion is filtered with an all-pass filter to produce a phase-shift, and then the unfiltered and filtered signals are mixed. The phaser effect was originally a simpler implementation of the flanger effect since delays were difficult to implement with analog equipment. Phasers are often used to give a "synthesized" or electronic effect to natural sounds, such as human speech. The voice of C-3PO from Star Wars was created by taking the actor's voice and treating it with a phaser.
• Chorus - a delayed signal is added to the original signal with a constant delay. The delay has to be short in order not to be perceived as echo, but above 5 ms to be audible. If the delay is too short, it will destructively interfere with the un-delayed signal and create a flanging effect. Often, the delayed signals will be slightly pitch shifted to more realistically convey the effect of multiple voices.
• Equalization - different frequency bands are attenuated or amplified to produce desired spectral characteristics. Abbreviated EQ.
• Filtering - Equalization is a form of filtering. In the general sense, frequency ranges can be emphasized or attenuated using low-pass, high-pass, band-pass or band-stop filters. Band-pass filtering of voice can simulate the effect of a telephone because telephones use band-pass filters.
• Overdrive effects such as the use of a fuzz box can be used to produce distorted sounds, such as for imitating robotic voices or radiotelephone traffic. The most basic overdrive effect involves clipping the signal when its absolute value exceeds a certain threshold.
• Pitch shift - similar to pitch correction, this effect shifts a signal up or down in pitch. For example, a signal may be shifted an octave up or down. This is usually applied to the entire signal and not to each note separately. One application of pitch shifting is pitch correction. Here a musical signal is tuned to the correct pitch using digital signal processing techniques. This effect is ubiquitous in karaoke machines and is often used to assist pop singers who sing out of tune. It is also used intentionally for aesthetic effect in such pop songs as Cher's Believe and Madonna's Die Another Day.
• Time stretching - the opposite of pitch shift, that is, the process of changing the speed of an audio signal without affecting its pitch.
• Resonators - emphasize harmonic frequency content on specified frequencies.
• Synthesizer - generate artificially almost any sound by either imitating natural sounds or creating completely new sounds.
• Modulation - to change the frequency or amplitude of a carrier signal in relation to a predefined signal. Ring modulation, also known as amplitude modulation, is an effect made famous by Doctor Who's Daleks and commonly used throughout sci-fi.
• Compression - the reduction of the dynamic range of a sound to avoid unintentional fluctuation in the dynamics. Level compression is not to be confused with audio data compression, where the amount of data is reduced without affecting the amplitude of the sound it represents.
• 3D audio effects - place sounds outside the stereo basis
• Reverse echo - a swelling effect created by reversing an audio signal and recording echo and/or delay whilst the signal runs in reverse. When played back forward the last echos are heard before the effected sound creating a rush like swell preceding and during playback. Jimmy Page of Led Zeppelin claims to be the inventor of this effect which can be heard in the bridge of Whole Lotta Love. Foley is the art of sound effects.

Genre: a class or category of artistic endeavor having a particular form, content, technique, or the like. In all art forms, genres are vague categories with no fixed boundaries. Genres are formed by sets of conventions, and many works cross into multiple genres by way of borrowing and recombining these conventions. The scope of the word "genre" is usually confined to art and culture, particularly literature. In genre studies the concept of genre is not compared to originality. Rather, all works are recognized as either reflecting on or participating in the conventions of genre.
Following this definition, think of the many MANY combinations that are possible within EDM / Electronic music.
Bellow are many genres of EDM in no specific order.

Breaks: Breakbeat (sometimes breakbeats or breaks) is a term used to describe a collection of sub-genres of electronic music, usually characterized by the use of a non-straightened 4/4 drum pattern (as opposed to the steady beat of house or trance). These rhythms may be characterized by their intensive use of syncopation and polyrhythms, which are prominent in all music of African origin, including African American music although the actual instruments used in breakbeat music makes it more closely related to techno and other forms of electronic music than African or African-American genres.

Chill Out: A number of compilations with "Chill Out" in their titles were released in the mid-1990s and beyond, helping to establish the genre as being very closely related to downtempo and trip hop but also incorporating, especially in the early 2000s, slower varieties of house music, nu-jazz, psybient, and lounge music. The genre also includes some forms of trance music, ambient music, and IDM, and it has entirely subsumed the older genre Balearic Beat, although that term is still used interchangeably with chill out. Chill out (sometimes called "soft techno") is generally tonal, relaxing (or at least not as "intense" as other music from the styles it draws from), and generally does not incorporate music that emphasizes "hard," "deep," or particularly hypnotic rhythms, although when used to describe the music played in chillout rooms at raves, it can also encompass extremely psychedelic experimental sounds of great variety.

Deep House: a style of house music. It is defined by several characteristics that distinguish it from most other forms of house music. These include calmer percussion, achieved by less compressed kick drums and softer hihats, as well as gentler transitions and simpler drum programming. The tempo of tracks is also relatively slower, ranging from around 110 to 128 bpm). The Jazz influences of deep house are most frequently brought out by sustained augmented or diminished chords which span several bars, which give the tracks a slightly dissonant feel. The use of vocals is also more common in deep house than in other forms of house music.

Drum & Bass / Jungle: Drum and bass (commonly abbreviated to d&b, DnB, dnb, drum n bass and drum & bass) is a type of electronic dance music also known as jungle. Emerging in the early 1990s, the genre is characterized by fast tempo broken beat drums (generally between 160–180 beats per minute) with heavy, often intricate basslines. Today, drum and bass is still considered an underground musical style, but its currents of influence run throughout popular music and culture.
Drum and bass began as an offshoot of the United Kingdom breakbeat hardcore and rave scene of the late 1980s, and over the first decade of its existence there have been many permutations in its style, incorporating elements from ragga, dancehall, electro, funk, hip hop, house, jazz, heavy metal, reggae, rock, techno and trance.

Dubstep & Grime: The genre typically uses dark, minor key sounds, but the major distinguishing elements of dubstep are an almost omnipresent subbass, use of samples, the fact it is largely instrumental, and a characteristic propulsive, sparse rhythm. Dubstep rhythms are usually syncopated, and often shuffled or incorporating triplets. The tempo is nearly always in the range of 138-142bpm.
Dubstep rhythms typically do not follow a four-to-the-floor pattern similar to many other styles of electronic dance music, but instead tend to miss out beats and repeat sets of two bars rather than single bars. Often, the rhythm will follow a pattern which when played alone will appear to be playing at half the tempo of the track, but the double-time feel is achieved by other elements, usually the bassline (a prime example being Skream's Rottan, which features a very sparse rhythm, comprised almost entirely of kick drum, snare drum, and very occasional hi-hat, with a distinctly half time feel implying a 69bpm tempo; the track is propelled by a constant subbass following a four to the floor 138bpm pattern)

House: House music is a style of electronic dance music that was developed by dance club DJs in the midwestern United States city of Chicago in the early to mid-1980s. House music is strongly influenced by elements of the late 1970s soul- and funk-infused dance music style of disco. House music takes disco's use of a prominent bass drum on every beat and developed a new style by mixing in a heavy electronic synthesizer bassline, electronic drums, electronic effects, funk and pop samples, and reverb (or delay)-enhanced vocals.

Electro House: Electro house (also known as dirty house, electrotech, and often shortened to electro) is a subgenre of house music that rose to become one of the most prominent genres of electronic dance music in 2004-06. Stylistically, it combines the four to the floor beats commonly found in House music with harmonically rich analogue basslines, abrasive high-pitched leads and the occasional piano or string riff. The tempo of electro house ranges approximately from 125 to 135 bpm.

Electronica: A style of music which allows easy focus on rhythmic elements that seem to be made of the most necessary sounds in order to create momentum that flows with long tonal passages. Every element of sound in electronica is usually very clear, and therefore works in this genre are usually very well crafted with great attention to detail.

Hard Dance: The tempo within Hard Dance usually ranges from 135 BPM (Techno) to 180 BPM (Freeform Hardcore). Hard Dance is an umbrella term that refers to the grouping of modern electronic dance music genres including Hard House, Nu-NRG, Hard-NRG, Hard Trance, Hardstyle, Jumpstyle & Freeform Hardcore. UK Hardcore & UK Techno is often included in this capacity. the style of music is one where the lines between some of the above mentioned genres are so blurred that it becomes near impossible to attribute it to one genre. A common example would be a Hard House / Hard Trance cross-over.

Hardcore: Hardcore is a style of electronic music that originated in the early-to-mid-1990s in multiple locations including Rotterdam, New York City and Newcastle, Australia. The style is typified by a fast tempo (160-240 beats per minute is common, and the rhythmic use of distorted and atonal industrial-like beats and samples.

Hip-Hop: Typically, hip hop music consists of rhythmic lyrics making use of techniques like assonance, alliteration, and rhyme. The rapper is accompanied by an instrumental track, usually referred to as a "beat", performed by a DJ, created by a producer, or one or more instrumentalists. Historically, this beat has often been created using a sample of the percussion break of another song: usually funk and soul recordings have been utilized. However, in recent years, it has become more common for the beat to be built up from individual drum samples. In addition to the beat, other sounds are often sampled, synthesized, or performed. Sometimes a track can be instrumental, as a showcase of the skills of the DJ or producer.

Minimal Techno: A minimalist sub-genre of Techno music, is characterized by a stripped-down, glitchy sound, simple 4/4 beats (usually around 120-135 BPM), repetition of short loops, and subtle changes. Related styles include Detroit techno, ambient techno, microhouse and tech house.
Minimal techno features consonant harmony, but most tracks lack functional chord progression, sometimes to the point of seeming atonal. Melodies, when present, are usually short loops of one or two bars, and emphasis is put on creating layers of unique sounds. Musical development is achieved mostly by adding or removing instruments (sounds) on eight-bar phrase boundaries and adjusting sound effects. Music created under this genre can range from melodic beautiful harmonies with a prominent bass line, to glitchy, unstructured, disjointed sounds which are unified to create an organized new track.

Progressive House: Consists of the 4-to-4 beat of house music with deeper, dub-influenced basslines and a more melancholic, emotional edge. Often, it featured elements from many different genres mixed together. Song of Life, for instance, has a trip-hop like down-pitched breakbeat and a high-energy Roland TB-303 riff at various stages.

Psy-Trance: Psychedelic trance generally has a fast tempo, in the range 135 to 150 BPM. The emphasis in psychedelic trance is placed strongly on purely synthesized timbres for programming and lead melodies. This form of electronic music developed from Goa trance in the early 1990s when it first began hitting the mainstream.

Tech House: As a musical (as opposed to a mixing) style, tech-house uses the same basic structure as house; however, elements of the house 'sound' such as realistic jazz sounds (in deephouse) and booming kick drums are replaced with elements from techno such as shorter, deeper, darker and often distorted kicks, smaller, quicker hi-hats, noisier snares and more synthetic or acid sounding synth melodies including raw electronic noises from distorted sawtooth and square wave oscillators.

Techno: Techno is a form of electronic dance music that became prominent in Detroit, Michigan during the mid-1980s with influences from Chicago house, electro, New Wave, funk and futuristic fiction themes that were prevalent and relative to modern culture during the end of the Cold War. "Techno" is commonly confused with general terms such as electronic music and dance music.
Techno features an overwhelming feeling of percussive, synthetic sounds, studio effects used as principal instrumentation, and, usually, a regular, 4/4 beat usually with a tempo of 130–140, sometimes faster, but rarely slower. Some techno compositions have strong melodies and bass lines, but these features are not as essential to techno as they are to other dance genres, and it is not uncommon for techno compositions to deemphasize or omit them.

Trance: A style of electronic music that developed in the 1990s. Trance music is generally characterized by a tempo of between 130 and 150 bpm, featuring repeating melodic synthesizer phrases, and a musical form that builds up and down throughout a track, often crescendoing or featuring a breakdown. Sometimes vocals are also utilized. The style is arguably derived from a combination of largely electronic music such as ambient music, techno, and house. 'Trance' received its name from the repetitious morphing beats, and the throbbing melodies which would presumably put the listener into a trance-like state.

Yeah, pvc. Pure chemistry man. Same thing as plastic drainage tubes. Or plastic bottles (the ones that are put togheter from two halfs, not the ones with a blowpoint at the bottom like coke bottles)...
Errr, the things chemistry are good for...